Ice making device

ABSTRACT

There is provided an ice making device in which any fluctuation in the amount of ice to be scraped off is nullified so that lump-shaped ice is prevented from being produced and damage to the scraper is prevented. In the ice making device configured in such a way that salt water that flows through a space between an inner pipe and a rotating cylinder is cooled by a cooling medium via the inner pipe so that ice is produced on the inner surface of the inner pipe, and the produced ice is scraped off by an edge portion of the scraper so that sherbet ice is produced, the scraper is provided with a scraper main body that is disposed on the outer surface of the rotating cylinder and pivotally supported by a center axle thereof, as a pivotal center, that is in parallel with the center axis of the rotating cylinder and a scraper weighted body that is formed of a material having a specific gravity larger than that of the scraper main body and mounted in the scraper main body in such a way as to be situated between the pivotal center of the scraper and the edge portion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an ice making device and particularly to an ice making device for producing sherbet-like ice.

2. Description of the Related Art

When being transported, fishes are cooled with ice so that the freshness thereof is maintained; as ice for cooling fishes, sherbet-like ice (referred to sherbet ice, hereinafter) is often utilized instead of ice cubes. Because its particle is fine, sherbet ice melts away in a short time when it makes contact with fishes. Accordingly, because sherbet ice can cool fishes more quickly than ice cubes, deterioration in the freshness of fishes can be suppressed much more; moreover, because, unlike an ice cube, sherbet ice does not damage the surface of a fish, it has an advantage of being capable of maintaining superficially good appearances of fishes.

Moreover, like tap water, sherbet ice can be transported through a pipeline. Still moreover, only by, through a tube such as a hose, pouring sherbet ice into a container that contains fishes, sherbet ice can be filled into the space between fishes and the container. Furthermore, because, unlike an ice cube, it is not required to transport and crush a heavy block ice, sherbet ice has an advantage of being easily handled.

In producing sherbet ice, there is often utilized a method in which salt water flows on a heat-transfer surface cooled with a cooling medium, and ice produced on the heat-transfer surface is scraped off. In general, an ice making device utilizing this method is provided with a double pipe that consists of an outer pipe and an inner pipe between which a cooling medium is filled, and in which salt water that flows inside the inner pipe is cooled, a rotating cylinder that is disposed inside the double pipe and is driven by a motor to rotate, and a scraper that is fixed to the outer surface of the rotating cylinder and scrapes off ice produced on the inner surface of the inner pipe as the rotating cylinder rotates.

Ice produced on the inner surface of the inner pipe, which is a heat-transfer surface, becomes thick as time elapses, whereby it becomes difficult to scrape off the ice by the scraper; therefore, it is necessary to scrape off the ice when the ice is as thin as possible. Therefore, it is required to press the scraper against the inner surface of the inner pipe through predetermined contact force so as to scrape off ice produced on the inner surface of the inner pipe. Accordingly, to date, there has been proposed an ice making device in which the scraper is formed of resin, and by utilizing the elastic force of the scraper, predetermine contact force is given to the scraper (e.g., refer to DE10113395C1).

In the case where the contact force between the scraper and the inner surface of the inner pipe is obtained through the elastic force of the scraper, the scraper is contracted in the radial direction of the rotating cylinder so as to become slightly shorter than its natural length and is inserted into the inner pipe. In the case of a conventional ice making device configured in such a way as described above, the scraper is always contracted pressed against the inner surface of the inner pipe; therefore, assuming that there exists no fluctuation in the opposing distance between the inner surface of the inner pipe of the double pipe, the scraper can scrape off ice while always being in contact with the inner surface of the inner pipe through predetermined contact force.

In the conventional ice making device configured in such a way as described above, when the inner pipe of the double pipe is deformed to be an ellipse or the rotating cylinder eccentrically rotates, there occurs a fluctuation in the opposing distance between the inner surface of the inner pipe and the outer surface of the rotating cylinder, whereby there occurs a fluctuation in the contraction amount of the scraper. Thus, the contact force between the scraper and the inner surface of the inner pipe fluctuates; in some cases, there occurs a gap between the inner surface of the inner pipe and the scraper, whereby the contact force may completely be nullified. As a result, ice cannot sufficiently be scraped off, whereby there is produced thick ice on the inner surface of the inner pipe, which is a heat-transfer surface. Provided thick ice like this is scraped off, the scraper is damaged, and instead of sherbet ice, there is obtained large ice that cannot be utilized for cooling fishes.

SUMMARY OF THE INVENTION

The present invention has been implemented in order to solve the foregoing problems in a conventional ice making device; the objective thereof is to obtain an ice making device in which, by always giving a predetermined range of contact force between the scraper and the heat-transfer surface, any fluctuation in the scraping amount is nullified so that lump-shaped ice is prevented from being produced, and damage to the scraper is prevented.

An ice making device according to the present invention is provided with a double pipe that includes an outer pipe and an inner pipe contained in the outer pipe and in which a cooling medium flows through a space between the outer pipe and the inner pipe; a rotating cylinder that is contained in the inner pipe in such a way as to be concentric with the inner pipe and driven by a driving device so as to be able to rotate on a center axis thereof in a predetermined direction; and a scraper that is fixed to an outer surface of the rotating cylinder and has an edge portion that slidably makes contact with an inner surface of the inner pipe. The ice making device is configured in such a way that salt water that flows through a space between the inner pipe and the rotating cylinder is cooled by the cooling medium via the inner pipe so that ice is produced on the inner surface of the inner pipe, and the produced ice is scraped off from the inner surface by the edge portion of the scraper so that sherbet ice is produced. The ice making device is characterized in that the scraper includes a scraper main body that is disposed on the outer surface of the rotating cylinder and pivotally supported by a center axle thereof, as a pivotal center, that is in parallel with the center axis of the rotating cylinder and a scraper weighted body that is formed of a material having a specific gravity larger than that of the scraper main body and mounted in the scraper main body in such a way as to be situated between the pivotal center of the scraper and the edge portion.

In an ice making device according to the present invention, the scraper is provided with a scraper main body that is disposed on the outer surface of the rotating cylinder and pivotally supported by a center axle thereof, as a pivotal center, that is in parallel with the center axis of the rotating cylinder and a scraper weighted body that is formed of a material having a specific gravity larger than that of the scraper main body and mounted in the scraper main body in such a way as to be situated between the pivotal center of the scraper and the edge portion; therefore, even in the case where there occurs an error or a fluctuation in the distance between the inner surface of the inner pipe and the outer surface of the rotating cylinder, stable contact force can be exerted between the edge portion of the scraper and the inner surface of the inner pipe, based on centrifugal force that is exerted on the scraper weighted body. In consequence, high-quality sherbet ice can be produced.

The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory diagram illustrating the overall configuration of an ice making system utilizing an ice making device according to Embodiment 1 of the present invention;

FIG. 2 is a perspective view illustrating a rotating cylinder and a scraper of an ice making device according to Embodiment 1 of the present invention;

FIG. 3 is an explanatory diagram illustrating the configuration of a scraper of an ice making device according to Embodiment 1 of the present invention;

FIG. 4 is a perspective view of a scraper of an ice making device according to Embodiment 1 of the present invention;

FIG. 5 is an explanatory chart representing the temporal change in contact pressure exerted between a scraper and an inner pipe of an ice making device according to Embodiment 1 of the present invention;

FIG. 6 is an explanatory diagram illustrating the configuration of a scraper of an ice making device according to Embodiment 2 of the present invention;

FIG. 7 is an explanatory diagram illustrating the configuration of a scraper of an ice making device according to Embodiment 3 of the present invention;

FIG. 8 is an explanatory diagram illustrating the configuration of a scraper of an ice making device according to Embodiment 4 of the present invention;

FIG. 9 is an explanatory chart representing an ice making device according to a technology that is a basis of the present invention;

FIG. 10 is a perspective view of a rotating cylinder and a scraper of an ice making device according to a technology that is a basis of the present invention;

FIG. 11 is a perspective view of a scraper of an ice making device according to a technology that is a basis of the present invention; and

FIG. 12 is an explanatory chart representing the temporal change in contact pressure exerted between a scraper and an inner pipe of an ice making device according to a technology that is a basis of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Technology as a Basis of the Present Invention

In the first place, a technology that is a basis of an ice making device according to the present invention will be explained. FIG. 9 is an explanatory chart representing an ice making device according to a technology that is a basis of the present invention. In FIG. 9, an inner pipe 14 formed in a cylindrical shape is disposed inside an outer pipe 13 formed in a cylindrical shape; the inner pipe 14 and the outer pipe 13 configure a double pipe. In a space between the outer surface of the inner pipe 14 and the inner surface of the outer pipe 13, there is formed a cooling medium path 18 through which a cooling medium from a refrigerator (unillustrated) flows.

A rotating cylinder 16 is disposed inside the inner pipe 14; in a space between the inner surface of the inner pipe 14 and the outer surface of the rotating cylinder 16, there is formed a salt water path 17 through which salt water from an ice storage tank (unillustrated) flows. The inner surface of the inner pipe 14 forms a heat-transfer surface for cooling salt water in the salt water path 17 by use of a cooling medium in the cooling medium path 18.

The rotating cylinder 16 is driven by a driving motor (unillustrated) as a driving means to rotate clockwise (in the direction indicated by the arrow in FIG. 9). On the outer surface of the rotating cylinder 16, there is provided a plurality of scrapers 15 that are arranged in the circumference direction of the rotating cylinder 16 in such a way as to be spaced a predetermined distance apart from one another; the edges of the scrapers 15 make contact with the inner surface of the inner pipe 14 at predetermined contact force.

The scraper 15 is pivotably supported by a rod 41. The rod 41 is supported by a rod supporting plate 40 fixed to the rotating cylinder 16. FIG. 10 is a perspective view of a rotating cylinder and a scraper of an ice making device according to a technology that is a basis of the present invention.

As illustrated in FIG. 10, the outer surface of the rotating cylinder 16 supports eight rods 41 that are arranged in the circumference direction of the rotating cylinder 16 in such a way as to be spaced a predetermined distance apart from one another; each of the scrapers 15 is pivotably supported by the rod 41. A space of a predetermined distance is provided between each of the plurality of scrapers 15 that are arranged on one and the same rod 41; however, the respective spaces of a predetermined distance are included in the moving coverage of the other scrapers disposed on the other rods 41, and the whole area, of the inner surface of the inner pipe 14, in the axis direction thereof make contact with the respective edges of the scrapers 15.

FIG. 11 is a perspective view of the scraper 15 of an ice making device according to a technology that is a basis of the present invention. In FIG. 11, the scraper 15 is formed of resin and is provided with a rod engagement portion 151 that engages with the rod 41, an edge portion 152, and a foot portion 153. The rod engagement portion 151 engages with the rod 41, so that the scraper is pivotably supported by the rod 41. The foot portion 153 of the scraper 15 makes contact with the outer surface of the rotating cylinder 16; the edge portion 152 makes contact with the inner surface of the inner pipe 14 at predetermined contact force, by utilizing the elasticity of the resin that forms the scraper 15.

In the ice making device, according to a technology that is a basis of the present invention, that is configured in such a way as described above, a cooling medium from a refrigerator flows in the cooling medium path 18 formed in a space between the outer pipe 13 and the inner pipe 14, and salt water flows in the salt water path 17 formed in a space between the inner pipe 14 and the rotating cylinder 16. The salt water in the salt water path 17 is cooled by the cooling medium in the cooling medium path 18, by the intermediary of the inner surface of the inner pipe 14, so that ice 51 is produced on the inner surface of the inner pipe 14.

The ice 51 produced on the inner surface of the inner pipe 14 is scraped off from the inner surface of the inner pipe 14 by the edge portion 152 of the scraper 15 that rotates in the arrow direction in FIG. 9 along with the rotating cylinder 16, and becomes ice grains 52; then, the ice grains 52 are mixed with the salt water in the salt water path 17 to become sherbet ice. The sherbet ice formed in such a way as described above is transported to an ice storage tank (unillustrated) through a pipeline and is stored therein; the sherbet ice is taken out from the ice storage tank, as may be necessary.

In the foregoing ice making device according to a technology that is a basis of the present invention, the scraper 15 mounted on the outer surface of the rotating cylinder 16 is inserted into the inner pipe 14 in such a way that the free-state distance between the foot portion 153 and the edge portion 152 is shortened by 1.0 mm; the edge portion 152 makes contact with the inner surface of the inner pipe 14 at the contact force based on the elastic force, of the resin, that is produced by this amount of contraction.

Although depending on the kind of resin material that forms the scraper 15 and the size of the scraper 15, in general, the maximum contractible amount of the distance between the foot portion 153 and the edge portion 152 of the scraper 15 is approximately 4.0 mm with respect to the free-state distance. Thus, because the foregoing distance of the scraper 15 is preliminarily contracted by approximately 1.0 mm, it can be contracted by up to approximately 3.0 mm when the rotating cylinder 16 is inserted into the inner pipe 14; when the distance is further contracted, the scraper 15 may be broken.

FIG. 12 is an explanatory chart representing the temporal change in contact pressure exerted between the edge portion 152 of the scraper 15 and the inner surface of the inner pipe 14. In FIG. 12, Pd denotes setting contact force exerted between the edge portion 152 of the scraper 15 and the inner surface of the inner pipe 14 when the scraper 15 is contracted by approximately 1.0 mm and in contact with the inner surface of the inner pipe 14; the setting contact force is designed to be approximately 20.0 kg/scraper. Provided there exists no distortion in the inner pipe 14 and the rotating cylinder 16 and the rotation axis of the rotating cylinder 16 does not deviate from the center axis of the rotating cylinder 16, the setting contact force Pd is constant to be approximately 20.0 kg, regardless of elapse of time.

The scraper 15 formed of resin is designed with anticipation that, due to the pressure caused by the inner surface of the inner pipe 14, the contraction of 1.0 mm varies by approximately ±0.3 mm; therefore, at its maximum contraction amount of approximately 1.3 mm, the contact force becomes a maximum contact force Pmax (=approximately 26.0 kg), and at its minimum contraction amount of approximately 0.7 mm, the contact force becomes a minimum contact force Pmin (=approximately 14.0 kg). In the case where the variation width of the distance between the inner surface of the inner pipe 14 and the outer surface of the rotating cylinder 16 is within an allowable contraction variation width of the scraper 15, the contact force exerted between the edge portion 152 of the scraper 15 and the inner surface of the inner pipe 14 is within a range from the maximum contact force Pmax and the minimum contact force Pmin and varies periodically as the time elapses; however, no trouble is caused in operating the ice making device.

In this situation, provided the distance between the inner surface of the inner pipe 14 and the outer surface of the rotating cylinder 16 exceeds the design value by more than 0.3 mm, the contact force exerted between the edge portion 152 of the scraper 15 and the inner surface of the inner pipe 14 becomes smaller than the minimum contact force Pmin. In this case, ice cannot sufficiently be scraped off, whereby there is produced thick ice on the inner surface of the inner pipe, which is a heat-transfer surface. Provided thick ice like this is scraped off, the scraper is damaged, and instead of sherbet ice, there is obtained large ice that cannot be utilized for cooling fishes.

Additionally, provided the distance between the inner surface of the inner pipe 14 and the outer surface of the rotating cylinder 16 becomes smaller than the design value by more than 0.3 mm, the contact force exerted between the edge portion 152 of the scraper 15 and the inner surface of the inner pipe 14 exceeds the maximum contact force Pmax. In this case, some abnormality may occur on the edge portion 152 of the scraper 15 or the inner surface of the inner pipe 14. For example, provided the scraper 15 that has been contracted by 1.0 mm is further contracted by 3.0 mm or more, as described above, the scraper 15 may be broken.

Embodiment 1

Next, an ice making device according to Embodiment 1 of the present invention will be explained. FIG. 1 is an explanatory diagram illustrating the overall configuration of an ice making system utilizing an ice making device according to Embodiment 1 of the present invention. In FIG. 1, an ice making device 12 is provided with an outer pipe 13, an inner pipe 14, and a rotating cylinder 16 that are formed in the same manner as the foregoing ice making device according to a technology that is a basis of the present invention. On the outer surface of the rotating cylinder 16, there is provided a plurality of scrapers 15, described later, that is the feature of the present invention.

In a space between the outer surface of the inner pipe 14 and the inner surface of the outer pipe 13, there is formed a cooling medium path 18 through which a cooling medium from a refrigerator 30 flows; in a space between the inner surface of the inner pipe 14 and the outer surface of the rotating cylinder 16, there is formed a salt water path 17 through which salt water from an ice storage tank 3 flows. The upper portion of the cooling medium path 18 is connected with a compressor 31 of the refrigerator 30 via a cooling-medium gas pipeline 33; the lower portion of the cooling medium path 18 is connected with a condenser 32 of the refrigerator 30 via a cooling-medium liquid pipeline 34. In cooling-medium liquid pipeline 34, there is provided an expansion valve 35.

Cooling medium liquid is supplied from the condenser 32 to the inside of the cooling medium path 18 via the expansion valve 35; the cooling medium liquid exchanges heat with salt water in the salt water path 17, so that it is gasified. The gasified cooling medium gas returns to the compressor 31 via the cooling-medium gas pipeline 33, compressed by the compressor 31, and then liquefied by the condenser 32.

The upper portion of the salt water path 17 of the ice making device 12 is connected with the upper portion of the ice storage tank 3 via a forward-stream sherbet pipeline 20; the lower portion of the salt water path 17 is connected with the ice storage tank 3 via a backward-stream sherbet pipeline 21. A circulating pump 23 is connected with the backward-stream sherbet pipeline 21. The lower portion of the ice storage tank 3 is connected with a discharging pipeline 10 having a discharging pump 11.

Salt water 1 in the ice storage tank 3 is supplied through the backward-stream sherbet pipeline 21 to the inside of the salt water path 17 of the ice making device 12 by means of the circulating pump 23; sherbet ice 2 in the salt water path 17 is supplied to the inside of the ice storage tank 3 through the forward-stream sherbet pipeline 20. A mixer 4 provided in the ice storage tank 3 rotates by being driven by a driving device 5 so as to constantly or appropriately mix the salt water 1 with the sherbet ice 2. Through the discharging pipeline 10, the sherbet ice 2 is discharged from the ice storage tank 3 by the discharging pump 11.

FIG. 2 is a perspective view illustrating the rotating cylinder 16 and the scraper 15 of the ice making device 12. In FIG. 2, eight (in FIG. 2, only six scrapers are illustrated) scrapers 15 are provided on the outer surface of the rotating cylinder 16. The arrangement of the scrapers 15 will be described in detail. There are provided scraper columns 150 each including two scrapers 15 arranged spaced apart from each other in the axis direction of the rotating cylinder 16; the scraper columns 150 are arranged at four places that are spaced 90° apart from one another in the circumferential direction of the rotating cylinder 16.

The mounting positions, in the axis direction of the rotating cylinder 16, of two scrapers 15 in each scraper column 150 are set in such a way as to correspond to positions, in the adjacent scraper columns 150, where no scraper 15 exists. As a result, as the rotating cylinder 16 rotates, the whole inner surface of the inner pipe 14 makes contact with the edges of the scrapers 15. In addition, FIG. 2 illustrates just an example of arrangement of the scrapers 15; therefore, the arrangement can be changed in accordance with the ice making capacity or the like of the ice making device 12.

FIG. 3 is an explanatory diagram illustrating the configuration of a scraper of an ice making device according to Embodiment 1 of the present invention; FIG. 4 is a perspective view of a scraper of an ice making device according to Embodiment 1 of the present invention. In FIGS. 3 and 4, the scraper 15 is provided with a scraper main body 63 that is pivotably supported by a rod 41 and a scraper weighted body 62 that is mounted in the scraper main body 63 and has a specific gravity larger than that of the scraper main body 63. The rod 41 is fixed on the outer surface of the rotating cylinder 16 in such a way that the center axis thereof is in parallel with the center axis, of the rotating cylinder 16, on which the rotating cylinder 16 rotates; therefore, the scraper main body 63 can pivot on its center axis, as a pivoting center, that is in parallel with the center axis of the rotating cylinder 16. The scraper weighted body 62 is mounted in the scraper main body 63 in such a way as to be situated between the pivoting center and an edge portion 61 of the scraper.

The scraper main body 63, formed of resin, is provided with a U-shaped groove 631 having oblique sidewalls 6311 in the side face portion of the edge portion 61. The scraper weighted body 62 is formed of metal such as a stainless steel; the oblique sidewall 6311 in the U-shaped groove 631 of the scraper main body 63 prevents the scraper weighted body 62 from moving in a direction perpendicular to the axis direction of the scraper 15. The scraper weighted body 62 can be replaced by another scraper weighted body, as may be necessary, by being pulled out from the scraper main body 63 in the axis direction of the scraper main body 63. The scraper weighted body 62 may be adhered in the U-shaped groove 631 of the scraper main body 63.

Each of the scrapers 15 mounted on the outer surface of the rotating cylinder 16 can freely pivot around the rod 41. Accordingly, the rotating cylinder 16, on the outer surface of which the scrapers 15 are mounted, can readily be inserted into the inner pipe 14, being held at the position where the respective edge portions 61 of the scrapers 15 do not make contact with the inner surface of the inner pipe 14.

Being configured as described above, when the ice making device 12 is operated, the rotating cylinder 16 contained in the inner pipe 14 is driven by a driving motor 19 at a predetermined side so as to rotate in the direction indicated by the arrow in FIG. 9. Centrifugal force, which is determined by the radial distance between the center of the rotating cylinder 16 and the gravity center of the scraper 15, the angular velocity of the rotating cylinder 16, and the mass of the scraper 15, is exerted on each of the scrapers 15; therefore, the edge portion 61 makes contact with the inner surface of the inner pipe 14 at predetermined contact force based on the centrifugal force, and slides on the inner surface of the inner pipe 14 in the rotation direction of the rotating cylinder 16.

The gravity center and the mass of the scraper 15 can be adjusted through the mass of the scraper weighted body 62, and the contact force exerted between the edge portion 61 and the inner surface of the inner pipe 14 can be controlled by controlling the rotation speed of the rotating cylinder 16. Therefore, by selecting the rotation speed of the rotating cylinder 16, the contact force exerted between the edge portion 61 and the inner surface of the inner pipe 14 can readily become equal to the contact force of 20.0 kg in the foregoing ice making device according to a technology that is a basis of the present invention.

FIG. 5 is an explanatory chart representing the temporal change in contact pressure exerted between a scraper and an inner pipe of an ice making device according to Embodiment 1 of the present invention. As represented in FIG. 5, when the rotation speed of the rotating cylinder 16 is selectively set to “High”, “Middle”, or “Low”, the contact force exerted between the edge portion 61 of the scraper 15 and the inner surface of the inner pipe 14 is set to be P1, P2, or P3 in accordance with the rotation speed. In the case where the rotation speed of the rotating cylinder 16 is constant, the contact force P1, P2, or P3 is a constant value, regardless of the elapse of time.

In this situation, provided, due to distortion in the inner pipe 14 or in the rotating cylinder 16, eccentricity of the rotating cylinder 16, or the like, the distance between the inner surface of the inner pipe 14 and the outer surface of the rotating cylinder 16 fluctuates, the centrifugal force exerted on the scraper 15 fluctuates; therefore, the contact force exerted between the edge portion 61 and the inner surface of the inner pipe 14 fluctuates. However, because the amount of fluctuation itself in the foregoing distance is minute, the amount of fluctuation in the contact force is also minute. Accordingly, the contact force exerted between the edge portion 61 of the scraper 15 and the inner surface of the inner pipe 14 does not become so large that the inner pipe 14 is damaged. Moreover, because the scraper 15 can pivot around the rod 41, it is made possible to keep the edge portion 61 always in contact with the inner surface of the inner pipe 14, regardless the fluctuation in the foregoing distance.

As described above, the scraper of an ice making device according to Embodiment 1 of the present invention makes it possible that, even in the case where the distance between the inner surface of the inner pipe 14 and the outer surface of the rotating cylinder 16 fluctuates, the edge portion 61 can constantly make contact with the inner surface of the inner pipe 14 at an appropriate strength of contact force. Moreover, the rotation speed of the rotating cylinder 16 is controlled in accordance with the production state of ice on the inner surface of the inner pipe 14, so that the contact force exerted between the edge portion 61 and the inner surface of the inner pipe 14 can be adjusted; thus, the scraper is not damaged, and sherbet ice can be produced constantly in the optimum conditions.

Embodiment 2

FIG. 6 is an explanatory diagram illustrating the configuration of a scraper of an ice making device according to Embodiment 2 of the present invention. In FIG. 6, a scraper weighted body 62 formed of a metal material such as a stainless steel and formed in a cylindrical rod shape is buried in a scraper main body 63 in such a way as to be inserted into a through-hole 631 formed in the axis direction of the scraper main body 63. The other configurations are the same as those in Embodiment 1.

The scraper weighted body 62 is configured in such a way that it can move in the axis direction of a scraper 15; therefore, as may be necessary, the scraper weighted body 62 can be replaced by another scraper weighted body, by being pulled out from the scraper main body 63. The scraper weighted body 62 may be adhered in the through-hole 631 of the scraper main body 63.

The ice making device, according to Embodiment 2 of the present invention, configured in such a way as described above makes it possible that, even in the case where the distance between the inner surface of an inner pipe 14 and the outer surface of a rotating cylinder 16 fluctuates, an edge portion 61 can constantly make contact with the inner surface of the inner pipe 14 at an appropriate strength of contact force. Moreover, the rotation speed of the rotating cylinder 16 is controlled in accordance with the production state of ice on the inner surface of the inner pipe 14, so that the contact force exerted between the edge portion 61 and the inner surface of the inner pipe 14 can be adjusted; thus, the scraper is not damaged, and sherbet ice can be produced constantly in the optimum conditions.

Embodiment 3

FIG. 7 is an explanatory diagram illustrating the configuration of a scraper of an ice making device according to Embodiment 3 of the present invention. In FIG. 7, at both side ends of a scraper weighted body 62 formed of a metal material such as a stainless steel, there are formed u-shaped grooves 621 and 622 each having oblique sidewalls. A u-shaped protrusion 631 is formed at a side end of a scraper main body 63; the scraper weighted body 62 is mounted on a side end of the scraper main body 63 in such a way that the U-shaped groove 621 thereof engages with the u-shaped protrusion 631 of the scraper main body 63.

The scraper weighted body 62 is configured in such a way that it can move in the axis direction of a scraper 15; therefore, as may be necessary, the scraper weighted body 62 can be replaced by another scraper weighted body, by being pulled out from the scraper main body 63. The scraper weighted body 62 may be adhered to the u-shaped protrusion 631 of the scraper main body 63.

A scraper tip 64, formed of resin, is provided with a u-shaped protrusion 641 and an edge portion 61 that makes contact with the inner surface of an inner pipe 14. The scraper tip 64 is mounted on a side end of the scraper weighted body 62 in such a way that the u-shaped protrusion 641 thereof engages with the u-shaped groove 622 of the scraper main body 62. The scraper tip 64 is configured in such a way that it can be pulled out in the axis direction of the scraper weighted body 62; therefore, as may be necessary, the scraper tip 64 can be replace by another scraper tip. The other configurations are the same as those in Embodiment 1.

The ice making device, according to Embodiment 3 of the present invention, configured in such a way as described above makes it possible that, even in the case where the distance between the inner surface of the inner pipe 14 and the outer surface of a rotating cylinder 16 fluctuates, the edge portion 61 can constantly make contact with the inner surface of the inner pipe 14 at an appropriate strength of contact force. Moreover, the rotation speed of the rotating cylinder 16 is controlled in accordance with the production state of ice on the inner surface of the inner pipe 14, so that the contact force exerted between the edge portion 61 and the inner surface of the inner pipe 14 can be adjusted; thus, the scraper is not damaged, and sherbet ice can be produced constantly in the optimum conditions.

Still moreover, the scraper tip 64 can be replaced by another scraper tip when the replacement is required, for example, due to wear of the edge portion 61; therefore, sherbet ice can be produced constantly in the optimum conditions.

Embodiment 4

FIG. 8 is an explanatory diagram illustrating the configuration of a scraper of an ice making device according to Embodiment 4 of the present invention. In FIG. 8, a scrapers 15 is configured with a scraper main body 63 formed of resin and a scraper weighted body 62 mounted in a U-shaped groove 631 formed in the side end portion, of the scraper main body 63, at the side of an edge portion 61. The scraper main body 63 is pivotably engaged with a rod 41 at a rod engagement portion 151.

The scraper weighted body 62 is formed of metal such as a stainless steel; an oblique sidewall 6311 in the U-shaped groove 631 of the scraper main body 63 prevents the scraper weighted body 62 from moving in a direction perpendicular to the axis direction of the scraper 15; however, the scraper weighted body 62 is configured in such a way that it can move in the axis direction of the scraper 15. Accordingly, as may be necessary, the scraper weighted body 62 can be replaced by another scraper weighted body, by being pulled out from the scraper main body 63. The scraper weighted body 62 may be adhered in the U-shaped groove 631 of the scraper main body 63. The other configurations are the same as those in Embodiment 1.

A scraper nail 65 formed integrally in the scraper main body 63 can make contact with the outer surface of the rotating cylinder 16. As described above, the contact force exerted between the edge portion 61 of the scraper 15 and the inner surface of the inner pipe 14 becomes a constant value determined by centrifugal force exerted on the scraper 15; however, in some cases, thick ice is produced on the inner surface of the inner pipe 14. On that occasion, it is required to scrape off the thick ice by strongest possible force. When such thick ice is produced, the front end portion of the scraper nail 65 makes contact with the outer surface of the rotating cylinder 16 so as to prevent the scraper 15 from pivoting clockwise. As a result, strong contact force obtained by combining centrifugal force and elastic force exerted by the scraper is produced between the edge portion 61 and the ice, so that the ice can be scraped off.

In addition, a scraper similar to the scraper according to Embodiments 3 may be provided in an ice making device according to any one of Embodiments 1 to 3, and in an ice making device according to any one of Embodiments 1, 2, and 4, an attachable and detachable scraper tip having the edge portion 61 may be provided.

INDUSTRIAL APPLICABILITY

An ice making device according to the present invention can be applied to an ice making system for producing sherbet ice.

Various modifications and alterations of this invention will be apparent to those skilled in the art without departing from the scope and spirit of this invention, and it should be understood that this is not limited to the illustrative embodiments set forth herein. 

1. An ice making device comprising: a double pipe that includes an outer pipe and an inner pipe contained in the outer pipe and in which a cooling medium flows through a space between the outer pipe and the inner pipe; a rotating cylinder that is contained in the inner pipe in such a way as to be concentric with the inner pipe and driven by a driving device so as to be able to rotate on a center axis thereof in a predetermined direction; and a scraper that is fixed to an outer surface of the rotating cylinder and has an edge portion that slidably makes contact with an inner surface of the inner pipe, the ice making device being configured in such a way that salt water that flows through a space between the inner pipe and the rotating cylinder is cooled by the cooling medium via the inner pipe so that ice is produced on the inner surface of the inner pipe, and the produced ice is scraped off from the inner surface by the edge portion of the scraper so that sherbet ice is produced, wherein the scraper includes a scraper main body that is disposed on the outer surface of the rotating cylinder and pivotally supported by a center axle thereof, as a pivotal center, that is in parallel with the center axis of the rotating cylinder and a scraper weighted body that is formed of a material having a specific gravity larger than that of the scraper main body and mounted in the scraper main body in such a way as to be situated between the pivotal center of the scraper and the edge portion.
 2. The ice making device according to claim 1, wherein the scraper weighted body is mounted at a side end portion, of the scraper main body, that is distal from the pivotal center of the scraper main body.
 3. The ice making device according to claim 1, wherein the scraper weighted body is buried in the scraper main body.
 4. The ice making device according to claim 1, wherein the scraper includes an attachable and detachable scraper tip having the edge portion.
 5. The ice making device according to claim 1, wherein the scraper includes a scraper nail capable of making contact with the outer surface of the rotating cylinder. 